The technical principles of the Base64 framework in the Java library
In the development of Java applications, the Base64 framework is widely used in data encoding and decoding scenarios, especially in network transmission and encryption algorithms.This article will conduct in -depth investigation of the technical principles of the Base64 framework in the Java library and provide relevant Java code examples.
1. Base64 Introduction
Base64 is a encoding method that converts binary data into printed characters. It consists of 64 characters, including letters (A-Z, A-Z), numbers (0-9), and two special characters (+and/).The base64 encoding transforms 3 -byte data to 4 BASE64 characters to reduce the data size, and can restore the original data through the corresponding decoding algorithm.
2. Base64 framework in the Java class library
The Java class library provides Base64 encoding and decoding related classes, such as Base64, Base64.encoder, and Base64.Decoder.The Base64 is a default implementation of Base64 encoding and decoding, and the Base64.encoder class is used for data coding, and the Base64.Decoder class is used for data decoding.
3. Base64 encoding principle
The base64 encoding divides the input bytes into a group of 3 bytes, and converts each group of bytes into 4 Base64 characters.If the number of bytes is not a multiples of 3, fill in the equal number (=) at the end to ensure that the data length of the encoding is 4.
The following is an example code that uses the Base64 in the Java class library:
import java.util.Base64;
public class Base64Example {
public static void main(String[] args) {
String originalString = "Base64 encoding and decoding in Java";
byte[] originalBytes = originalString.getBytes();
// base64 encoding
String encodedString = Base64.getEncoder().encodeToString(originalBytes);
System.out.println("Base64 encoded string: " + encodedString);
// base64 decoding
byte[] decodedBytes = Base64.getDecoder().decode(encodedString);
String decodedString = new String(decodedBytes);
System.out.println("Base64 decoded string: " + decodedString);
}
}
In the above example, first, the original string is converted to byte array.Then, use the Getencoder () method of Base64 to return a base64.encoder object, call its Encodetostring () method to encode the byte array, and save the result in the ENCODEDSTRING variable.Then, use the Base64 GetDecoder () method to return a base64.decoder object, call its decode () method to decoding the encoded string, and finally convert the decoding byte array to string.
4. Base64 decoding principle
In contrast to coding, the Base64 decoding process converts 4 BASE64 characters into 3 bytes of data.If you encounter an equal number (=) when decoding, the corresponding bytes are filled by bytes, and the decoding process will ignore these filled bytes.
The following is an example code that uses the Base64 in the Java Library to decoding:
import java.util.Base64;
public class Base64Example {
public static void main(String[] args) {
String encodedString = "QmFzZTY0IGVuY29kaW5nIGFuZCBkZWNvZGluZyBpbiBKYXZh";
byte[] encodedBytes = encodedString.getBytes();
// base64 decoding
byte[] decodedBytes = Base64.getDecoder().decode(encodedBytes);
String decodedString = new String(decodedBytes);
System.out.println("Base64 decoded string: " + decodedString);
}
}
In the above example, first, the encoded string is converted to byte array.Then, use the Base64 GetDecoder () method to return a base64.decoder object, call its decode () method to decoding the byte array, and save the result in the decodedBytes variable.Finally, the decoding byte array is converted to a string.
5. The application of Base64 in the network transmission and encryption algorithm
Because the data coded data only contains printed characters, data transmission can be easily transmitted in network transmission to avoid the processing of special characters.In addition, the base64 encoding is often used for the key transmission, digital signature and message certification in encryption algorithm.
In summary, the Base64 framework provides a simple way for data coding and decoding in the Java library.Through in -depth understanding of the technical principles of Base64, we can better apply the Base64 framework to achieve the implementation of data security transmission and encryption algorithm.
